Field of the Invention
The invention relates to a drive for a freight elevator, particularly for a stair climber for the handicapped, being guided on at least one supporting waling or spar.
Known stair climbers as a rule have two supporting walings, on which the load-receiving configuration or the elevator or lift for the handicapped is guided through the use of rollers. The drive of the load-receiving configuration is carried out, for instance, in force-locking fashion (German Patent DE-PS 29 14 350) through a special drive waling or spar or through rollers that rest in stationary fashion on the supporting walings and are driven, or are disposed in form-locking fashion (German Patent DE-PS 31 03 162) in stationary fashion on or in the supporting walings. A form-locking connection is one which connects two elements together due to the shape of the elements themselves, as opposed to a force-locking connection, which locks the elements together by force external to the elements. The force-locking drive using paired opposed rollers that engage the supporting spars or walings requires considerable contact pressure and a corresponding load capacity of the bearing, as well as wear-resistant material, and is therefore correspondingly expensive.